ration of insects, worms, fishes, and amphibious animals; the second to the respiration of birds, of quadrupeds, and of man. We have so recently noticed the experiments of Spallanzani on the subject of the respiration of insects, &c. whom indeed Mr. Ellis principally follows, that we need say no more than that in most of the main facts he agrees with the Italian philosopher. We ourselves ventured to suggest that some errors had found their way in the experiments from which Spal Janzani concluded that snails consume a small portion of the nitrogenous portion of the air. Mr. Ellis has more minutely criticized these experiments; and has shown that the results of different trials are so discordant that little dependance can be placed upon them. If to this we oppose the contradictory and apparently decisive experiments of Vauquelin, there will be little hazard in believing that nature is uniform, and that insects in general like other ani. mals leave the nitrogen of the air they breathe unaltered.

Many have been the attempts to estimate the quantity of air taken into the lungs by a single natural inspiration; and the various and inconsistent conclusions of different experimentalists shows the extreme difficulty of arriving at certainty, though the natural obstacles seem to be far from insurmountable. The lowest estimate makes the quantity about 12 cubic inches; the highest raises it to 40. The weight of numbers favours the latter computation. The mode of conducting the experiment adopted by Dr. Menzies is deemed by Mr. Ellis to be the most unexceptionable; who likewise makes it amount nearly to forty inches. Mr. Ellis has taken much pains to collect and compose the statements of different writers on the principal facts regarding human respiration. He concludes on the whole that the greatest diminution of the capacity of the chest will bear to its greatest expansion the proportion of 41 to 241 nearly. If the same quantity of air be repeatedly respired it loses more, and more of its bulk; and it would seem that the diminution proceeds in higher ratio, the longer it has been respired. Mr. Davy attributes this to a rapid absorption of the elastic fluid through the moist coats of the pulmonary veins.'

It happens rather unfortunately for this opinion,' observes Mr. Ellis, that in the natural respiration of atmospheric air, a very small difference exists between the inspired and expired volumes, though the powers of absorption, if such there be, must then be acting in their greatest vigour; whilst under an almost total exhaustion of muscular and vital power, this aosorption is considered to take place in an extraordinary degree.'

But this is far from satisfactory: for undoubtedly if such an absorption takes place it must be reckoned a consequence of a pure chemical process, as much as the union of oxygen with carbon, according to Mr. Ellis's own hypothesis; and when the vital powers are in themselves perfect, there may be, and probably are, convulsive motions performed with more than patural force, the efforts of nature to make, every possible advantage of the unnatural situation in which the animal is placed. For our own parts we can see neither difficulty nor incongruity in supposing aerial substances to be absorbed by the animal fluids; and if further experiments should prove this not to be the case with regard to the oxygen inspired into the lungs, we should believe this to be more a mechanical effect than to proceed from a complete inaptitude to chemical union. Perhaps a thin layer of carbonic acid perpetually secreted from, or formed upon the surface of the lungs may prevent the oxygen from coming within the sphere of chemical action.

It must be conceded to Mr. Ellis that he has rendered it very probable that in the act of respiration the quantity of oxygen which disappears and that of carbonic acid which is produced are proportionate to each other. This however is far from proving the direct conversion of the one into the other. If a quantity of acid were poured upon marble, the proportion between the acid which disappears and the carbonic acid produced would be also constant. And though oxygen enters so largely into the composition of the carbonic acid, yet the union with carbon may so totally alter its properties, as indeed is the truth in common chemical experiments, that these substances may be deemed se. parate elements, acting upon any third substance with dif ferent degrees of affinity. Whether the whole of the oxygen which disappears is exactly equal to that which enters into the composition of the acid, is a point of the first consequence to determine, and which indeed would go very far towards settling the question. But on this head Mr. Ellis candidly acknowledges, that it has not hitherto been determined how much is the diminution of the bulk of the air by the act of respiration.

'Amid such contradictory results,' he observes, it is not to be expected that a conclusion can be drawn which shall truly express the amount of the diminution in question: and indeed, from a consideration of the powers which govern respiration, and the various circumstances which sensibly affect that process, we cannot but consider the actual loss of bulk which the air suffers by a single

respiration, as in its nature extremely difficult, if not impossible to determine.'

This is too strong perhaps; but till this is determined, all contention on the subject is but a fruitless war of words.

The fifth chapter treats of the source of the carbon which enters into the composition of the acid discovered after germination, &c. That it is furnished by the vegetable or animal body perhaps hardly required the formality of a proof. But Mr. Ellis has enriched this chapter by introducing the valuable experiment of M. Huber. This philosopher has observed that both nitrogen and hydrogen gas attract a carbonated matter, (carbon, says Mr. Ellis, but this is difficult of proof) from germinating seeds; which is converted into carbonic acid by oxygen, even in the temperature of the atmosphere. This valuable fact may perhaps afford a clue to unravel the mystery, in which these processes of nature are at present involved. But till common charcoal in its acknowledged form can be rendered soluble either in the natural gases or in water, to assume these compounds to be mere solutions of carbon is, we think, perfectly gratuitous.

In the course of the inquiry into the source of the carbon emitted from organised bodies, Mr. E. takes occasion to examine the different authorities for and against the excretion of air from the surface of the human body. Many emi. nent physiologists have thought, that carbonic acid exhaled from this surface, and that the purity of the air contiguous to it was diminished. He concludes on the whole that there is no aeriform perspiration; and that the facts which have been adduced in support of this hypothesis are fallacious. This is a conclusion which we do not feel inclined to controvert.

Mr. Ellis attributes to the exhalent vessels of the lungs the power of omitting the carbon, which is changed into carbonic acid. This is a very useless speculation, since according to his own concessions, no organised structure is necessary to the formation of the acid. A clot of blood, scum, or even the shell of the egg is found quite adequate to produce this effect, when in contact with atmospheric air,

Mr. Ellis concludes his Inquiry with considerations on the phenomena which arise from the changes induced on the air by the living functions of vegetables and animals. The heat which is produced, and which in various degrees is common to all organized and living beings, is the most important of these. Heat is evolved by germination, by vegetation, CRIT. REV. Vol. 14. July, 1809. Y

and by the respiration of animals. Mr. Ellis attributes the evolution of heat to the great specific heat of oxygen gas, and the consequent extrication of it, by its change into carbonic acid. He adopts then without modification the ingeni ous theory of Dr. Crauford. But we meet with no facts with which those who have paid attention to the obscure and intricate subject are not already familiar. Perhaps we ought from this to except the experiments of M. Huber concerning the heat given out by the spadices of the arum corifolium during the process of fecundation. This plant grows in Madagascar and the Isle of France. By tying five of these spadices round the bulb of a thermometer the mercury was raised near 600 (if there be no error in the numbers) above that in another, which was used as a standard of comparison. When twelve flowers were used, the heat was still by several degrees greater. This power of producing heat is much greater in the male part of the spadices than in the female. It appears that this singular property is confined to the exterior surfaces of the spadices, for the pith, when the exterior surface has been reinoved does not raise the thermometer; and the exterior surfaces, under this treatment, still retain their power. It is absolutely necessary to this production of heat, that the atmosphere should be in contact with the surface; and the air is greatly deteriorated by the process. There certainly appears then to be a strong analogy to animal respiration in a process carried on by vegetable organs. We wish Mr. Ellis had taken the trouble to reduce his thermometrical degrees to Farenheit's scale. We find different scales used in two successive pages; without the smallest advertisement to the reader on the subject.

We think Mr. Ellis has occasionally indulged too much in jejune and hypothetical reasonings; insomuch that we have found it sometimes irksome to follow him. But the philosophical inquirer will feel obliged to him for having brought together such a mass of valuable information on a most important subject of research; and if he has destroyed the delusion of some false but pleasing theories he has re placed it by demonstrating the universal harmony which exists among all organized and animated beings, and the admirable simplicity of nature in producing the most complicated and stupendous results.

MONTHLY CATALOGUE.

RELIGION.

ART. 17.-A Sermon preached in the Parish Church of St. Paul, Bedford, before the Rev. Dr. Shepherd, Archdeacon, at the annual Visitation of the Clergy, held on Thursday, the 12th of May, 1808. By the Rev. Joshua Morton, Vicar of Risely, in the County of Bedford, and Chaplain to his Royal Highness the Prince of Wales. 4to. Rivington. 1808.

THE very uncharitable, very injudicious, and, as we think, illegal sentence which has lately been passed on Mr. Stone, by a prelate, who, at a public visitation some years ago, recommended his clergy to study the writings of a male and a female methodist, videlicet, Mr. William Wilberforce, and Miss or Mrs. Hannah More, seems to have operated on many timid or interested members in the establishment, a more than usual propensity to forsake the light of reason, of learning, and of criticism; and to run open-mouthed after favour and preferment in the labyrinth of mystery. Original sin, Trinity, and Atonement, are the favourite terms, the hocus pocus of methodism, which he who can bray out from the pulpit with the least meaning and the most sound, is sure to be heard with most attention, and to be cried up to the skies as an orthodox divine; that is, a divine without three clear ideas in his head; but with a countless stock of intolerance in his heart. What is comanonly called orthodoxy,is nothing but a compound of words, without sense, but which are strung together with metaphoric ribbands, till the gew-gaw pleases the eye of ignorance, and the deluded multitude, who mistake appearance for reality, show for substance, and sound for sense, turn up their eyes and wonder with a stupid look of praise. This kind of orthodoxy, though it may make fools stare, and hypocrites whine, will excite the indignation of the wise, and the sorrow of the good. For true religion is a plain thing, which a plain man may understand. It has no mysteries, no obscurity, no perplexing doctrines, no indefinite phraseology. It is the gift of the Father of lights; and it is indeed in the truths which it teaches, and the precepts which it inculcates as clear to the mind and conscience of man, as the lustre of the sun is to his corporeal sight. But, says Mr. Morton- Can the fact that GoD was manifested in the flesh to redeem mankind, be objected to because it is mysterious? The mystery is with God, the blessing is ours. Shall not he who caters for the sparrow, be allowed to pur sue his own methods when he stoops to save a world?' Without